Safety device for prime movers, especially for steam turbines



Dec. 4, 1923, 1,476,100

w. PAPE SAFETY nnvzcs FOR PRIME movsns, ESPECIALLY-FOR smm'wunsmas Fil dApril 1a. 1922 A'Iilf flit Enter.- Wilhelm Papa, y

.Hi's Attorney Patented Dec. 4, 1923.

warren stares:

WILHELH PAPE, or

eairant'crrics.

GHARLOTTENBURG, ennianitv, iessrenon TO GENERAL nnno'rnrc COMPANY, A CORPOBATZON or NEW YORK.

SAFETY DEVICE FOR CPR-TEE MQVEBS, ESPECIALLY FOR STEAM TURBINES.

Application filed. April 1.8, 1922. Serial No. 555,248.

To aZZ whom it may concern:

Be it known that I, WILHELM' PAPE, a citizen of the German Republic, residing at 69 Niebuhrstrasse, in the city of Charlottenburg, Province of Brandenburg, State of Prussia, Germany, have invented a new and useful Safety Device for Prime Movers, Especially for Steam Turbines (for which I have filed an application in Germany June 1, 1917), of which the following is a specification.

My invention relates to an improved safety device for prime movers, more especially for steam turbines- It is common practice to provide steam turbines with an emergency valve mechanism to keep them' from racing. Such mechanisms in most cases comprise a valve biased toward closed position, a locking device or catch for bold:

ing vit-open against the biasing force, and.

gine from racing. The fact'that all parts of the safety device are at rest during the normal running of the engine -makes it more subject to jamming. This latter evil is not overcome by operating the mechanism fre- -q{u,ently by hand, as by this means the emergency governor is not worked. This latterdoes not change its position until the engine exceeds the speed for which the gov. ernor is set, that is not until the engine. is actually racing.

The object of my-invention is to provide an improved structure and arrangement whereby I obtain a higher degree of safety. from racing than has heretofore been ob-v tained. I obtain this object by introducing an additional safety device, which is also influenced by the speed of the engine, and which actuates either the same or a second quick closing valve. Inthis casetwo separate locking devices or. catches may be'operated by either the same or byan additional emergency governor; or an additional valuable improvement may be obtained by using the standard engine governor, instead of using an additional emergency v governor. This latter improvement will cause the engine to be under the influence of a governor which is always in motion and always under control of the engineer. This combination will act if the enginesurpasses the speed limit and will be independent of the original emergency governor. Any damage or dirt interfering with the operation of a standard governor will instantly cause the engine to run irregularly by causing it to alternately speed up and slow down and can always be adjusted in time before the governor would give out completely. g h

In the drawing the figure is adiagrammatic View of an elastic fluid turbine having a governing mechanismeinbodying my invention.

Referring to the drawing, 1 indicates a known type of emergency governor carried by the shaft 1 of the turbine. T. It comprises a plunger 1 which is normally held within the confines of the shaft by aspring 1 and is thrown outward by centrifugal forcein case of excess speed to engage a trip finger 1. Trip finger 1 is connected to the catch or locking device 2 of a quick closing emergency valve 2 by means of a rod 3. Valve 2* is biased to closed position by aspring 2? and is adapted to be held open against the biasing force by catch 2 the arrangement being such that in case 0 excess speed plunger 1 is thrown out .by centrifugal force to strike trip finger 1 thereby pulling on rod 3 and moving catch 2 to release valve 2 and permit it to close. This is a known arrangement of emergency valve (rear and is to be taken as typical of any suitable apparatus of this type.

The turbine is provided with a speed governor 4 having its governor lever l connected to the pilot valve l of a servomotor, the connections including a usual form of follow-up connections. The piston 4 of the servo-motor is connected to a regulating valve mechanism i which controls the admission of elastic fluid-through conduit i to the turbine; The speed governor, servo-motor and valve mechanism may be of any suitable type, the arrangement illustrated being a known one, the operation of which is well understood.

In conduit 4 is a valve 5 having its stem connected to a piston 6 located in a cylinder 6. Valve 5 is biasedto closed position bya spring 6 I against the action of spring 6 by fluid pres sure admitted to cylinder 6* beneath piston 6 by a pipe 7. Pipe 7 connects to a valve casing? in which is a valve 8 adapted to connect pipe-7 either to a sourceof fluid 7 pressure represented by pipeS or to a re gion' of lower pressure represented by discharge pipe 10." The stem 9 of valve 8 is connected to or forms a continuation of the stem of pilot valve 42. In pipe 7 is a valve cylinder '6 ,"whereby valve 5 isheld open;

The varrangement is such that'with increase in speed governor 4iraises pilot valve 4 whereby motive fluid-j will be admitted above'piston"'i moving it downward and valve mechanism 4 toward closed position soas to admit less motive fluid to the turbine. With decrease in speed the operation isth'e same-'eXcept'that it is in the opposite direction; In case th eturbine starts racing, speed governor 4.111 moving the pilotvalve will move valve 8 upward to a point beyond the end of pipe 7, thereby cutting off com munica-tion between pipe 7 and pipe 8 and connecting" pipe 7 to discharge pipe 10. The pressure under piston 6 will escape inrmediatelythrougnpipe 7 and-1O where .uponspring 6* will close valve 5. At the same time the emergency governor 1 will eiiecttheclosing of valve 2 and the servomotor will effect the closing'oi valve mechanism)? Preferably as a source of pressure for pipe'8 ,-1*utilize the oil pressure of the forced feed lubricating system for the turbine. /Vith' this arrangement, in case the pressure of the lubricating system fails valve5 will be closed and'the turbine thus shut down.

By turning by hand the three-way'valve or cock'll located in pipe'7,this pipe may be opened to the atmosphere, permitting the pressure under-piston 6 to escape and valve 5-to"c"lose.

It willbe seen that thi whole second Valve '5 is normally held open safety device is created by the simple ad- -dition of pipe Iand by adding anew bonw net to pistonfi. .This small addition to the piston valve 8 arealways' action and in constant motion, as long as the en ine-i running, so that these ares-mea der can tinuous observati'or'i andiareunlikely to fail. By the use of hydraulic power transmission for valve 5', auxiliary apparatus, such as air cushions'for brakingthe impact ofthe quick closing'valve, is unnecessary because the liquid itself While""being *displaced ffro iir underneath the piston acts asa dashpottqff effect a'gradual. closing ofthe valve.-

Inaccor'dance' with the provisions of the patent statutes, Ifhave described the prin ciple of operationof my inventiom'together with the apparatus which-I newton-steerto represent the best e'nibodiment thereof, but I desire to have it understood that' t-he' apparatus shown is only'illustrativeiand' that the invention may be carriedout "by other means. i i f What I claim as new and desire to secure by Letters Patent of the United States,is:

1. The combination with "a' prime mover, of aregulating valve controlling the admis' sion of elastic fluid thereto, aUspeedfgov-j' ernor for' the regulating valve, 'ainj'em'e'rgency valve controlling 'the admission of elastic fluid to the prime mover, Midineans'ji operated by said speed governor for-effect ing the closing of the emergency valve 2. r The combination with prime mover, of a regulating valve controlling the admissionof elastic fluid thereto, a speed overnor for the regulating valve, an emergency 'valve controlling, the 'admission'of elasti'c'nfl'uid to the prime mover, means biasingit' to closed position, fluid-operated means for holding itopen against the biasin'gfforc'', and means operated by said speed governor for relieving the pressure on sa'i'dQfluid-op erated means when the speed reaches-a predetermined high' rate. 1 3. The combination with a prime mover having a fluid admission conduit, of ai'eg ulatingvalve mechanism insai'd conduit, 2 speed" governor, a servo-motor'fthrough which the speed governor controls" {sa-id regulating valve, a quickclosing valve in said conduit, an emergency governor for effecting the closing of it, a second quick closing valve in said conduit, and means actuated by the speed of the prime mover for effecting the closing of said second quick closing valve.

4. The combination with a prime mover having a fluid admission conduit, of a regulating valve mechanism in said conduit,

a speed governor, a servo-motor through which the speed governor controls said regulating valve, a quick closing valve in said conduit, an emergency governor for effecting the closing of it, a second quick closing valve in said conduit, means biasing it toward closed position, fluid-operated means for holding 1t open against said biasing means, and speed governor-operated means controlling the fluid-operated means.

I, 5. The combination with a prime mover having a fluid admission conduit, of a regu-- lating valve mechanism in said conduit, a' speed governor for operating 1t, a (111101! closing valve in said conduit, fluid pressure actuated means for holding it open, and means operated by said speed governor which at normal. speed connects said fluid pressure-actuated means to a source of fluid,

WILHELM PAPE. 

